Bottom Line:
The 44 kinds of SERS IDs were able to generate simple codes and could possibly generate more than one million kinds of codes by incorporating combinations of different SERS IDs.The SERS ID encoding based screening platform can identify the peptide ligand on the bead and also quantify its binding affinity for specific protein.We believe that our SERS barcoding technology is a promising method in the screening of one-bead-one-compound (OBOC) libraries for drug discovery.

Affiliation: Interdisciplinary Program in Nano-Science and Technology, Seoul National University, Seoul 151-744, Republic of Korea.

ABSTRACTRecently, preparation and screening of compound libraries remain one of the most challenging tasks in drug discovery, biomarker detection, and biomolecular profiling processes. So far, several distinct encoding/decoding methods such as chemical encoding, graphical encoding, and optical encoding have been reported to identify those libraries. In this paper, a simple and efficient surface-enhanced Raman spectroscopic (SERS) barcoding method using highly sensitive SERS nanoparticles (SERS ID) is presented. The 44 kinds of SERS IDs were able to generate simple codes and could possibly generate more than one million kinds of codes by incorporating combinations of different SERS IDs. The barcoding method exhibited high stability and reliability under bioassay conditions. The SERS ID encoding based screening platform can identify the peptide ligand on the bead and also quantify its binding affinity for specific protein. We believe that our SERS barcoding technology is a promising method in the screening of one-bead-one-compound (OBOC) libraries for drug discovery.

Mentions:
Figure 1a shows the peptide-encoding strategy. Many sets of peptide sequences were synthesized on commercially available TentaGel (TG) beads (~35 μm). After the synthesis, the TG beads were swollen with NMP solution. The swollen volume of TG bead in NMP was ~2.5 times larger compared to dried TG bead. The swollen TG beads were then mixed with the corresponding SERS ID dispersion for 10 min to confer the SERS codes to the specific peptide-TG beads, which were physically adsorbed on the TG bead surfaces. The TG beads were then washed several times with ethanol, which acted as a shrinking agent, resulting in collapse of polymer chains of TG bead with the SERS IDs. Scanning electron microscope (SEM) image of the peptide-TG beads showed clean and smooth surfaces before SERS encoding (Fig. 1b). However, after the encoding process, the SERS IDs (~200 nm, TEM image is shown in Fig. 1c) were adsorbed and buried halfway onto the TG bead surfaces via solvent-driven swelling and shrinking process, as shown in Fig. 1d (37,000 dots/single bead in average could be loaded). The buried structure indicates that the SERS IDs might be bridging the polymer chains of the TG beads. The formation of a polymer chain bridge with the SERS IDs on the TG beads could potentially enhance the stability of the SERS IDs.

Mentions:
Figure 1a shows the peptide-encoding strategy. Many sets of peptide sequences were synthesized on commercially available TentaGel (TG) beads (~35 μm). After the synthesis, the TG beads were swollen with NMP solution. The swollen volume of TG bead in NMP was ~2.5 times larger compared to dried TG bead. The swollen TG beads were then mixed with the corresponding SERS ID dispersion for 10 min to confer the SERS codes to the specific peptide-TG beads, which were physically adsorbed on the TG bead surfaces. The TG beads were then washed several times with ethanol, which acted as a shrinking agent, resulting in collapse of polymer chains of TG bead with the SERS IDs. Scanning electron microscope (SEM) image of the peptide-TG beads showed clean and smooth surfaces before SERS encoding (Fig. 1b). However, after the encoding process, the SERS IDs (~200 nm, TEM image is shown in Fig. 1c) were adsorbed and buried halfway onto the TG bead surfaces via solvent-driven swelling and shrinking process, as shown in Fig. 1d (37,000 dots/single bead in average could be loaded). The buried structure indicates that the SERS IDs might be bridging the polymer chains of the TG beads. The formation of a polymer chain bridge with the SERS IDs on the TG beads could potentially enhance the stability of the SERS IDs.

Bottom Line:
The 44 kinds of SERS IDs were able to generate simple codes and could possibly generate more than one million kinds of codes by incorporating combinations of different SERS IDs.The SERS ID encoding based screening platform can identify the peptide ligand on the bead and also quantify its binding affinity for specific protein.We believe that our SERS barcoding technology is a promising method in the screening of one-bead-one-compound (OBOC) libraries for drug discovery.

Affiliation:
Interdisciplinary Program in Nano-Science and Technology, Seoul National University, Seoul 151-744, Republic of Korea.

ABSTRACTRecently, preparation and screening of compound libraries remain one of the most challenging tasks in drug discovery, biomarker detection, and biomolecular profiling processes. So far, several distinct encoding/decoding methods such as chemical encoding, graphical encoding, and optical encoding have been reported to identify those libraries. In this paper, a simple and efficient surface-enhanced Raman spectroscopic (SERS) barcoding method using highly sensitive SERS nanoparticles (SERS ID) is presented. The 44 kinds of SERS IDs were able to generate simple codes and could possibly generate more than one million kinds of codes by incorporating combinations of different SERS IDs. The barcoding method exhibited high stability and reliability under bioassay conditions. The SERS ID encoding based screening platform can identify the peptide ligand on the bead and also quantify its binding affinity for specific protein. We believe that our SERS barcoding technology is a promising method in the screening of one-bead-one-compound (OBOC) libraries for drug discovery.